附面层吸入式进气道内流动损失特性

用数值仿真手段，对进气道内流总压损失采用逐段对比分析的方法，研究了附面层吸入式（BLI）进气道相对于常规S弯进气道的内流总压损失特性。结果表明：进气道出口马赫数不变，较低来流马赫数和较高来流马赫数工况下（方案对应马赫数0.3以下和马赫数0.6以上），BLI进气道产生的流动损失比常规S弯进气道的大，差量达2.4%；中等来流马赫数工况下（本文方案对应马赫数0.3与马赫数0.6之间），BLI进气道产生的流动损失比常规S弯进气道的略小，差量在0.3%以内；流动损失特性间的差异是由于BLI进气道进口前壁面与进口低能附面流改变了进口段流动特性、及在S弯管道内发展的综合作用结果。

Flow losses characteristics of BLI inlet

In order to study the difference and mechanism of the internal flow total pressure loss between the boundary layer ingestion (BLI) inlet and the conventional S-shaped inlet, numerical simulation method was applied and step-by-step comparative analysis of the total pressure loss was carried out. The results showed that, when fan-face Mach number was kept unchanged, the flow loss of BLI inlet was larger than that of the conventional S-shaped inlet under the working conditions of relatively lower and higher Mach number of free-stream (corresponding to below 0.3 or above 0.6), and the maximum difference was 2.4 percent. Under the working condition of medium Mach number of free-stream (corresponding to between 0.3 and 0.6), the flow loss generated by the BLI inlet was slightly smaller than that of the conventional S-shaped inlet, and the maximum difference was 0.3 percent. The combined effect of the fore-wall of the BLI inlet and the low-energy boundary flow changed the flow characteristics in the inlet and developed rapidly in the diffuser of the S-shaped pipeline, leading to the difference in flow loss characteristics.